The present invention relates to a vehicle transmission having continuously variable transmission ratios, with a first conical disk pair disposed on a first shaft and a second conical disk pair disposed on a second shaft. A a belt means is disposed between the conical disk pairs, as well as an input shaft and an intermediate shaft. On the intermediate shaft an intermediate gear that can be brought in into rotational engagement with the input shaft and an output gear are rotatably supported and a connecting gear is disposed non-rotatably. Between the input shaft and the intermediate shaft a first torque transmission device is disposed, and between the input shaft and the intermediate gear a second torque transmission device is disposed. Between the intermediate gear and the output gear a third torque transmission device is disposed, and between the intermediate shaft and the output gear a fourth torque transmission device is disposed.
Based on the yet unpublished U.S. patent application 60/999,964 filed by the applicant, a generically relevant vehicle transmission with continuously variable gear ratio has been disclosed.
The transmission relates to a so-called i2-red-transmission, whereby “i” refers to the transmission ratio of a conical disk-belt transmission variator and “2” indicates that the transmission range of the speed variator is repeated twice.
In that manner a transmission with a large total transmission ratio can be attained, which can transmit a high drive torque.
Although the above-described transmission has already proven itself, it features the disadvantage of entailing a relatively complex design because it features five clutches altogether, of which one clutch is assigned to the reverse driving range although four clutches are necessary for the conical disk belt transmission that is repeated twice for a large total ratio. Those clutches must be activated accordingly, which leads to complicated shifting processes.
An object of the present invention is to simplify the generic vehicle transmission with respect to its design and thus the control of individual torque transmitting components of the transmission.